Many domestic and industrial appliances, such as sweepers and floor polishers, are used over large areas and have very long power cords which enable their use down long hallways to a location remote from where the power cord is plugged into a wall socket. In order to continue use of such an appliance, the operator must walk a long distance to unplug the cord, then walk back and plug the cord into a sequence of widely spaced wall outlets to complete the sweeping of polishing task. This consumes an excessive amount of unproductive time by the appliance operator.
There is a need for an appliance which does not require continual manual plugging and unplugging of the power cord. There have been many attempts to provide devices for enabling the remote unplugging of an appliance power cord by manipulating the power cord. Many of these have been patented, as evidenced by U.S. Pat. Nos. 2,394,618; 2,490,580; 2,456,548; 2,696,594; 2,986,719; 3,737,835; 3,936,123; 4,114,969; and 4,045,106. It is noteworthy that, although this problem was recognized at least as early as 1944, there has been no successful commercialized solution.
Thus, there is a need for a device which enables an appliance operator to unplug the appliance cord from a remote electrical socket by ejecting the plug from the socket without moving from the appliance.
There is also a need for such a device which is an integral part of the plug mounted on the end of the appliance power cord. There is also a need for such a device which is a self-contained unit which can be used with existing appliances having conventional plugs.
It would also be advantageous to incorporate vibration-sensing or tilt-sensing actuators for causing ejection of the plug from the socket to disconnect appliances during earthquakes or other building-damaging events to reduce the possibility of an appliance-caused fire.
Older electrical sockets tend to be corroded, which increases the frictional force with which it retains plug prongs. Also, plugs that have been used many times may be crimped due to many instances of off-axis removal. To accommodate the vast variety of forces needed to remove all plugs from all sockets, the solenoid effecting the ejection must be very strong, and, hence, large and expensive.
Thus, there is a need for a device which is compact and inexpensive, and which will reliably eject a plug from a socket.
There is also a need for a plug ejector which is an integral part of an extension cord that is adaptable to all existing appliances.
There is a further need for a plug ejector which does not require additional wiring, but utilizes an appliance's power supply wiring and switch to activate the plug ejector.